---
id: "CVE-2026-123511"
page: "https://infrastack.ai/live/CVE-2026-123511"
kind: "vulnerability"
aliases: ["CVE-2026-123511"]
title: "Vikunja: CalDAV requests can flood the database with dummy tasks"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["caldav", "package", "self-hosted", "vikunja"]
not_affected_if: ["auth-required", "managed-hosting", "no-caldav"]
published_at: "2026-11-08T02:16:39+00:00"
first_seen_at: "2026-11-08T02:21:08+00:00"
updated_at: "2026-11-08T02:25:23+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123511", "first_seen_at": "2026-11-08T02:21:08+00:00"}]
exploit_sources: []
---

# Vikunja: CalDAV requests can flood the database with dummy tasks

Link for people: https://infrastack.ai/live/CVE-2026-123511 (this .md is for agents)

Vikunja before 2.7.1 lets a logged-in CalDAV client send a single calendar to-do item with thousands of RELATED-TO properties, and each unknown related ID creates a task. An attacker can bloat the database and overload the event pipeline, which can slow or disrupt the service.

_Summary, check and fix written by a model from the sources; labelled as such._

## Fix

- Vikunja: move to `2.7.1` or later.

## Timeline

- 2026-11-08T02:21:08+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123511

## Documents

- [advisory] Vendor advisory: github.com https://github.com/go-vikunja/vikunja/security/advisories/GHSA-c934-xjq2-mrg3
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/vikunja-before-2.7.1-resource-exhaustion-via-caldav-vtodo-related-to-entries

## From the sources

Vikunja before 2.7.1 contains an uncontrolled resource consumption vulnerability that allows authenticated CalDAV clients to create unbounded dummy tasks by sending VTODOs with thousands of RELATED-TO properties. Attackers can repeat unknown related UIDs in a single PUT request to generate thousands of task, relation, and event rows, bloating the database and overloading the event pipeline.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_